/Engine/Source/Editor/UnrealEd/Public/Editor.h
Delegate type for when a user requests to delete certain assets... DOES NOT mean the asset(s) will be deleted (the user could cancel)
typedef TMulticastDelegate_OneParam< void, const [TArray](API\Runtime\Core\Containers\TArray)< [UObject](API\Runtime\CoreUObject\UObject\UObject) * > & > FOnAssetsPreDelete